<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<title>Source code</title>
<link rel="stylesheet" type="text/css" href="../../../../../../stylesheet.css" title="Style">
</head>
<body>
<div class="sourceContainer">
<pre><span class="sourceLineNo">001</span>package org.apache.commons.net.ntp;<a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.3"></a>
<span class="sourceLineNo">004</span> * contributor license agreements.  See the NOTICE file distributed with<a name="line.4"></a>
<span class="sourceLineNo">005</span> * this work for additional information regarding copyright ownership.<a name="line.5"></a>
<span class="sourceLineNo">006</span> * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.6"></a>
<span class="sourceLineNo">007</span> * (the "License"); you may not use this file except in compliance with<a name="line.7"></a>
<span class="sourceLineNo">008</span> * the License.  You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
<span class="sourceLineNo">017</span> */<a name="line.17"></a>
<span class="sourceLineNo">018</span><a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.util.ArrayList;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.util.List;<a name="line.21"></a>
<span class="sourceLineNo">022</span><a name="line.22"></a>
<span class="sourceLineNo">023</span>/**<a name="line.23"></a>
<span class="sourceLineNo">024</span> * Wrapper class to network time packet messages (NTP, etc) that computes<a name="line.24"></a>
<span class="sourceLineNo">025</span> * related timing info and stats.<a name="line.25"></a>
<span class="sourceLineNo">026</span> *<a name="line.26"></a>
<span class="sourceLineNo">027</span> * @author Jason Mathews, MITRE Corp<a name="line.27"></a>
<span class="sourceLineNo">028</span> *<a name="line.28"></a>
<span class="sourceLineNo">029</span> * @version $Revision: 1299238 $<a name="line.29"></a>
<span class="sourceLineNo">030</span> */<a name="line.30"></a>
<span class="sourceLineNo">031</span>public class TimeInfo {<a name="line.31"></a>
<span class="sourceLineNo">032</span><a name="line.32"></a>
<span class="sourceLineNo">033</span>    private final NtpV3Packet _message;<a name="line.33"></a>
<span class="sourceLineNo">034</span>    private List&lt;String&gt; _comments;<a name="line.34"></a>
<span class="sourceLineNo">035</span>    private Long _delay;<a name="line.35"></a>
<span class="sourceLineNo">036</span>    private Long _offset;<a name="line.36"></a>
<span class="sourceLineNo">037</span><a name="line.37"></a>
<span class="sourceLineNo">038</span>    /**<a name="line.38"></a>
<span class="sourceLineNo">039</span>     * time at which time message packet was received by local machine<a name="line.39"></a>
<span class="sourceLineNo">040</span>     */<a name="line.40"></a>
<span class="sourceLineNo">041</span>    private final long _returnTime;<a name="line.41"></a>
<span class="sourceLineNo">042</span><a name="line.42"></a>
<span class="sourceLineNo">043</span>    /**<a name="line.43"></a>
<span class="sourceLineNo">044</span>     * flag indicating that the TimeInfo details was processed and delay/offset were computed<a name="line.44"></a>
<span class="sourceLineNo">045</span>     */<a name="line.45"></a>
<span class="sourceLineNo">046</span>    private boolean _detailsComputed;<a name="line.46"></a>
<span class="sourceLineNo">047</span><a name="line.47"></a>
<span class="sourceLineNo">048</span>    /**<a name="line.48"></a>
<span class="sourceLineNo">049</span>     * Create TimeInfo object with raw packet message and destination time received.<a name="line.49"></a>
<span class="sourceLineNo">050</span>     *<a name="line.50"></a>
<span class="sourceLineNo">051</span>     * @param message NTP message packet<a name="line.51"></a>
<span class="sourceLineNo">052</span>     * @param returnTime  destination receive time<a name="line.52"></a>
<span class="sourceLineNo">053</span>     * @throws IllegalArgumentException if message is null<a name="line.53"></a>
<span class="sourceLineNo">054</span>     */<a name="line.54"></a>
<span class="sourceLineNo">055</span>    public TimeInfo(NtpV3Packet message, long returnTime) {<a name="line.55"></a>
<span class="sourceLineNo">056</span>        this(message, returnTime, null, true);<a name="line.56"></a>
<span class="sourceLineNo">057</span>    }<a name="line.57"></a>
<span class="sourceLineNo">058</span><a name="line.58"></a>
<span class="sourceLineNo">059</span>    /**<a name="line.59"></a>
<span class="sourceLineNo">060</span>     * Create TimeInfo object with raw packet message and destination time received.<a name="line.60"></a>
<span class="sourceLineNo">061</span>     *<a name="line.61"></a>
<span class="sourceLineNo">062</span>     * @param message NTP message packet<a name="line.62"></a>
<span class="sourceLineNo">063</span>     * @param returnTime  destination receive time<a name="line.63"></a>
<span class="sourceLineNo">064</span>     * @param comments List of errors/warnings identified during processing<a name="line.64"></a>
<span class="sourceLineNo">065</span>     * @throws IllegalArgumentException if message is null<a name="line.65"></a>
<span class="sourceLineNo">066</span>     */<a name="line.66"></a>
<span class="sourceLineNo">067</span>    public TimeInfo(NtpV3Packet message, long returnTime, List&lt;String&gt; comments)<a name="line.67"></a>
<span class="sourceLineNo">068</span>    {<a name="line.68"></a>
<span class="sourceLineNo">069</span>            this(message, returnTime, comments, true);<a name="line.69"></a>
<span class="sourceLineNo">070</span>    }<a name="line.70"></a>
<span class="sourceLineNo">071</span><a name="line.71"></a>
<span class="sourceLineNo">072</span>    /**<a name="line.72"></a>
<span class="sourceLineNo">073</span>     * Create TimeInfo object with raw packet message and destination time received.<a name="line.73"></a>
<span class="sourceLineNo">074</span>     * Auto-computes details if computeDetails flag set otherwise this is delayed<a name="line.74"></a>
<span class="sourceLineNo">075</span>     * until computeDetails() is called. Delayed computation is for fast<a name="line.75"></a>
<span class="sourceLineNo">076</span>     * intialization when sub-millisecond timing is needed.<a name="line.76"></a>
<span class="sourceLineNo">077</span>     *<a name="line.77"></a>
<span class="sourceLineNo">078</span>     * @param msgPacket NTP message packet<a name="line.78"></a>
<span class="sourceLineNo">079</span>     * @param returnTime  destination receive time<a name="line.79"></a>
<span class="sourceLineNo">080</span>     * @param doComputeDetails  flag to pre-compute delay/offset values<a name="line.80"></a>
<span class="sourceLineNo">081</span>     * @throws IllegalArgumentException if message is null<a name="line.81"></a>
<span class="sourceLineNo">082</span>     */<a name="line.82"></a>
<span class="sourceLineNo">083</span>    public TimeInfo(NtpV3Packet msgPacket, long returnTime, boolean doComputeDetails)<a name="line.83"></a>
<span class="sourceLineNo">084</span>    {<a name="line.84"></a>
<span class="sourceLineNo">085</span>            this(msgPacket, returnTime, null, doComputeDetails);<a name="line.85"></a>
<span class="sourceLineNo">086</span>    }<a name="line.86"></a>
<span class="sourceLineNo">087</span><a name="line.87"></a>
<span class="sourceLineNo">088</span>    /**<a name="line.88"></a>
<span class="sourceLineNo">089</span>     * Create TimeInfo object with raw packet message and destination time received.<a name="line.89"></a>
<span class="sourceLineNo">090</span>     * Auto-computes details if computeDetails flag set otherwise this is delayed<a name="line.90"></a>
<span class="sourceLineNo">091</span>     * until computeDetails() is called. Delayed computation is for fast<a name="line.91"></a>
<span class="sourceLineNo">092</span>     * intialization when sub-millisecond timing is needed.<a name="line.92"></a>
<span class="sourceLineNo">093</span>     *<a name="line.93"></a>
<span class="sourceLineNo">094</span>     * @param message NTP message packet<a name="line.94"></a>
<span class="sourceLineNo">095</span>     * @param returnTime  destination receive time<a name="line.95"></a>
<span class="sourceLineNo">096</span>     * @param comments  list of comments used to store errors/warnings with message<a name="line.96"></a>
<span class="sourceLineNo">097</span>     * @param doComputeDetails  flag to pre-compute delay/offset values<a name="line.97"></a>
<span class="sourceLineNo">098</span>     * @throws IllegalArgumentException if message is null<a name="line.98"></a>
<span class="sourceLineNo">099</span>     */<a name="line.99"></a>
<span class="sourceLineNo">100</span>    public TimeInfo(NtpV3Packet message, long returnTime, List&lt;String&gt; comments,<a name="line.100"></a>
<span class="sourceLineNo">101</span>                   boolean doComputeDetails)<a name="line.101"></a>
<span class="sourceLineNo">102</span>    {<a name="line.102"></a>
<span class="sourceLineNo">103</span>        if (message == null) {<a name="line.103"></a>
<span class="sourceLineNo">104</span>            throw new IllegalArgumentException("message cannot be null");<a name="line.104"></a>
<span class="sourceLineNo">105</span>        }<a name="line.105"></a>
<span class="sourceLineNo">106</span>        this._returnTime = returnTime;<a name="line.106"></a>
<span class="sourceLineNo">107</span>        this._message = message;<a name="line.107"></a>
<span class="sourceLineNo">108</span>        this._comments = comments;<a name="line.108"></a>
<span class="sourceLineNo">109</span>        if (doComputeDetails) {<a name="line.109"></a>
<span class="sourceLineNo">110</span>            computeDetails();<a name="line.110"></a>
<span class="sourceLineNo">111</span>        }<a name="line.111"></a>
<span class="sourceLineNo">112</span>    }<a name="line.112"></a>
<span class="sourceLineNo">113</span><a name="line.113"></a>
<span class="sourceLineNo">114</span>    /**<a name="line.114"></a>
<span class="sourceLineNo">115</span>     * Add comment (error/warning) to list of comments associated<a name="line.115"></a>
<span class="sourceLineNo">116</span>     * with processing of NTP parameters. If comment list not create<a name="line.116"></a>
<span class="sourceLineNo">117</span>     * then one will be created.<a name="line.117"></a>
<span class="sourceLineNo">118</span>     *<a name="line.118"></a>
<span class="sourceLineNo">119</span>     * @param comment<a name="line.119"></a>
<span class="sourceLineNo">120</span>     */<a name="line.120"></a>
<span class="sourceLineNo">121</span>    public void addComment(String comment)<a name="line.121"></a>
<span class="sourceLineNo">122</span>    {<a name="line.122"></a>
<span class="sourceLineNo">123</span>        if (_comments == null) {<a name="line.123"></a>
<span class="sourceLineNo">124</span>            _comments = new ArrayList&lt;String&gt;();<a name="line.124"></a>
<span class="sourceLineNo">125</span>        }<a name="line.125"></a>
<span class="sourceLineNo">126</span>        _comments.add(comment);<a name="line.126"></a>
<span class="sourceLineNo">127</span>    }<a name="line.127"></a>
<span class="sourceLineNo">128</span><a name="line.128"></a>
<span class="sourceLineNo">129</span>    /**<a name="line.129"></a>
<span class="sourceLineNo">130</span>     * Compute and validate details of the NTP message packet. Computed<a name="line.130"></a>
<span class="sourceLineNo">131</span>     * fields include the offset and delay.<a name="line.131"></a>
<span class="sourceLineNo">132</span>     */<a name="line.132"></a>
<span class="sourceLineNo">133</span>    public void computeDetails()<a name="line.133"></a>
<span class="sourceLineNo">134</span>    {<a name="line.134"></a>
<span class="sourceLineNo">135</span>        if (_detailsComputed) {<a name="line.135"></a>
<span class="sourceLineNo">136</span>            return; // details already computed - do nothing<a name="line.136"></a>
<span class="sourceLineNo">137</span>        }<a name="line.137"></a>
<span class="sourceLineNo">138</span>        _detailsComputed = true;<a name="line.138"></a>
<span class="sourceLineNo">139</span>        if (_comments == null) {<a name="line.139"></a>
<span class="sourceLineNo">140</span>            _comments = new ArrayList&lt;String&gt;();<a name="line.140"></a>
<span class="sourceLineNo">141</span>        }<a name="line.141"></a>
<span class="sourceLineNo">142</span><a name="line.142"></a>
<span class="sourceLineNo">143</span>        TimeStamp origNtpTime = _message.getOriginateTimeStamp();<a name="line.143"></a>
<span class="sourceLineNo">144</span>        long origTime = origNtpTime.getTime();<a name="line.144"></a>
<span class="sourceLineNo">145</span><a name="line.145"></a>
<span class="sourceLineNo">146</span>        // Receive Time is time request received by server (t2)<a name="line.146"></a>
<span class="sourceLineNo">147</span>        TimeStamp rcvNtpTime = _message.getReceiveTimeStamp();<a name="line.147"></a>
<span class="sourceLineNo">148</span>        long rcvTime = rcvNtpTime.getTime();<a name="line.148"></a>
<span class="sourceLineNo">149</span><a name="line.149"></a>
<span class="sourceLineNo">150</span>        // Transmit time is time reply sent by server (t3)<a name="line.150"></a>
<span class="sourceLineNo">151</span>        TimeStamp xmitNtpTime = _message.getTransmitTimeStamp();<a name="line.151"></a>
<span class="sourceLineNo">152</span>        long xmitTime = xmitNtpTime.getTime();<a name="line.152"></a>
<span class="sourceLineNo">153</span><a name="line.153"></a>
<span class="sourceLineNo">154</span>        /*<a name="line.154"></a>
<span class="sourceLineNo">155</span>         * Round-trip network delay and local clock offset (or time drift) is calculated<a name="line.155"></a>
<span class="sourceLineNo">156</span>         * according to this standard NTP equation:<a name="line.156"></a>
<span class="sourceLineNo">157</span>         *<a name="line.157"></a>
<span class="sourceLineNo">158</span>         * LocalClockOffset = ((ReceiveTimestamp - OriginateTimestamp) +<a name="line.158"></a>
<span class="sourceLineNo">159</span>         *                     (TransmitTimestamp - DestinationTimestamp)) / 2<a name="line.159"></a>
<span class="sourceLineNo">160</span>         *<a name="line.160"></a>
<span class="sourceLineNo">161</span>         * equations from RFC-1305 (NTPv3)<a name="line.161"></a>
<span class="sourceLineNo">162</span>         *      roundtrip delay = (t4 - t1) - (t3 - t2)<a name="line.162"></a>
<span class="sourceLineNo">163</span>         *      local clock offset = ((t2 - t1) + (t3 - t4)) / 2<a name="line.163"></a>
<span class="sourceLineNo">164</span>         *<a name="line.164"></a>
<span class="sourceLineNo">165</span>         * It takes into account network delays and assumes that they are symmetrical.<a name="line.165"></a>
<span class="sourceLineNo">166</span>         *<a name="line.166"></a>
<span class="sourceLineNo">167</span>         * Note the typo in SNTP RFCs 1769/2030 which state that the delay<a name="line.167"></a>
<span class="sourceLineNo">168</span>         * is (T4 - T1) - (T2 - T3) with the "T2" and "T3" switched.<a name="line.168"></a>
<span class="sourceLineNo">169</span>         */<a name="line.169"></a>
<span class="sourceLineNo">170</span>        if (origNtpTime.ntpValue() == 0)<a name="line.170"></a>
<span class="sourceLineNo">171</span>        {<a name="line.171"></a>
<span class="sourceLineNo">172</span>            // without originate time cannot determine when packet went out<a name="line.172"></a>
<span class="sourceLineNo">173</span>            // might be via a broadcast NTP packet...<a name="line.173"></a>
<span class="sourceLineNo">174</span>            if (xmitNtpTime.ntpValue() != 0)<a name="line.174"></a>
<span class="sourceLineNo">175</span>            {<a name="line.175"></a>
<span class="sourceLineNo">176</span>                _offset = Long.valueOf(xmitTime - _returnTime);<a name="line.176"></a>
<span class="sourceLineNo">177</span>                _comments.add("Error: zero orig time -- cannot compute delay");<a name="line.177"></a>
<span class="sourceLineNo">178</span>            } else {<a name="line.178"></a>
<span class="sourceLineNo">179</span>                _comments.add("Error: zero orig time -- cannot compute delay/offset");<a name="line.179"></a>
<span class="sourceLineNo">180</span>            }<a name="line.180"></a>
<span class="sourceLineNo">181</span>        } else if (rcvNtpTime.ntpValue() == 0 || xmitNtpTime.ntpValue() == 0) {<a name="line.181"></a>
<span class="sourceLineNo">182</span>            _comments.add("Warning: zero rcvNtpTime or xmitNtpTime");<a name="line.182"></a>
<span class="sourceLineNo">183</span>            // assert destTime &gt;= origTime since network delay cannot be negative<a name="line.183"></a>
<span class="sourceLineNo">184</span>            if (origTime &gt; _returnTime) {<a name="line.184"></a>
<span class="sourceLineNo">185</span>                _comments.add("Error: OrigTime &gt; DestRcvTime");<a name="line.185"></a>
<span class="sourceLineNo">186</span>            } else {<a name="line.186"></a>
<span class="sourceLineNo">187</span>                // without receive or xmit time cannot figure out processing time<a name="line.187"></a>
<span class="sourceLineNo">188</span>                // so delay is simply the network travel time<a name="line.188"></a>
<span class="sourceLineNo">189</span>                _delay = Long.valueOf(_returnTime - origTime);<a name="line.189"></a>
<span class="sourceLineNo">190</span>            }<a name="line.190"></a>
<span class="sourceLineNo">191</span>            // TODO: is offset still valid if rcvNtpTime=0 || xmitNtpTime=0 ???<a name="line.191"></a>
<span class="sourceLineNo">192</span>            // Could always hash origNtpTime (sendTime) but if host doesn't set it<a name="line.192"></a>
<span class="sourceLineNo">193</span>            // then it's an malformed ntp host anyway and we don't care?<a name="line.193"></a>
<span class="sourceLineNo">194</span>            // If server is in broadcast mode then we never send out a query in first place...<a name="line.194"></a>
<span class="sourceLineNo">195</span>            if (rcvNtpTime.ntpValue() != 0)<a name="line.195"></a>
<span class="sourceLineNo">196</span>            {<a name="line.196"></a>
<span class="sourceLineNo">197</span>                // xmitTime is 0 just use rcv time<a name="line.197"></a>
<span class="sourceLineNo">198</span>                _offset = Long.valueOf(rcvTime - origTime);<a name="line.198"></a>
<span class="sourceLineNo">199</span>            } else if (xmitNtpTime.ntpValue() != 0)<a name="line.199"></a>
<span class="sourceLineNo">200</span>            {<a name="line.200"></a>
<span class="sourceLineNo">201</span>                // rcvTime is 0 just use xmitTime time<a name="line.201"></a>
<span class="sourceLineNo">202</span>                _offset = Long.valueOf(xmitTime - _returnTime);<a name="line.202"></a>
<span class="sourceLineNo">203</span>            }<a name="line.203"></a>
<span class="sourceLineNo">204</span>        } else<a name="line.204"></a>
<span class="sourceLineNo">205</span>        {<a name="line.205"></a>
<span class="sourceLineNo">206</span>             long delayValue = _returnTime - origTime;<a name="line.206"></a>
<span class="sourceLineNo">207</span>             // assert xmitTime &gt;= rcvTime: difference typically &lt; 1ms<a name="line.207"></a>
<span class="sourceLineNo">208</span>             if (xmitTime &lt; rcvTime)<a name="line.208"></a>
<span class="sourceLineNo">209</span>             {<a name="line.209"></a>
<span class="sourceLineNo">210</span>                 // server cannot send out a packet before receiving it...<a name="line.210"></a>
<span class="sourceLineNo">211</span>                 _comments.add("Error: xmitTime &lt; rcvTime"); // time-travel not allowed<a name="line.211"></a>
<span class="sourceLineNo">212</span>             } else<a name="line.212"></a>
<span class="sourceLineNo">213</span>             {<a name="line.213"></a>
<span class="sourceLineNo">214</span>                 // subtract processing time from round-trip network delay<a name="line.214"></a>
<span class="sourceLineNo">215</span>                 long delta = xmitTime - rcvTime;<a name="line.215"></a>
<span class="sourceLineNo">216</span>                 // in normal cases the processing delta is less than<a name="line.216"></a>
<span class="sourceLineNo">217</span>                 // the total roundtrip network travel time.<a name="line.217"></a>
<span class="sourceLineNo">218</span>                 if (delta &lt;= delayValue)<a name="line.218"></a>
<span class="sourceLineNo">219</span>                 {<a name="line.219"></a>
<span class="sourceLineNo">220</span>                     delayValue -= delta; // delay = (t4 - t1) - (t3 - t2)<a name="line.220"></a>
<span class="sourceLineNo">221</span>                 } else<a name="line.221"></a>
<span class="sourceLineNo">222</span>                 {<a name="line.222"></a>
<span class="sourceLineNo">223</span>                     // if delta - delayValue == 1 ms then it's a round-off error<a name="line.223"></a>
<span class="sourceLineNo">224</span>                     // e.g. delay=3ms, processing=4ms<a name="line.224"></a>
<span class="sourceLineNo">225</span>                     if (delta - delayValue == 1)<a name="line.225"></a>
<span class="sourceLineNo">226</span>                     {<a name="line.226"></a>
<span class="sourceLineNo">227</span>                         // delayValue == 0 -&gt; local clock saw no tick change but destination clock did<a name="line.227"></a>
<span class="sourceLineNo">228</span>                         if (delayValue != 0)<a name="line.228"></a>
<span class="sourceLineNo">229</span>                         {<a name="line.229"></a>
<span class="sourceLineNo">230</span>                             _comments.add("Info: processing time &gt; total network time by 1 ms -&gt; assume zero delay");<a name="line.230"></a>
<span class="sourceLineNo">231</span>                             delayValue = 0;<a name="line.231"></a>
<span class="sourceLineNo">232</span>                         }<a name="line.232"></a>
<span class="sourceLineNo">233</span>                     } else {<a name="line.233"></a>
<span class="sourceLineNo">234</span>                        _comments.add("Warning: processing time &gt; total network time");<a name="line.234"></a>
<span class="sourceLineNo">235</span>                    }<a name="line.235"></a>
<span class="sourceLineNo">236</span>                 }<a name="line.236"></a>
<span class="sourceLineNo">237</span>             }<a name="line.237"></a>
<span class="sourceLineNo">238</span>             _delay = Long.valueOf(delayValue);<a name="line.238"></a>
<span class="sourceLineNo">239</span>            if (origTime &gt; _returnTime) {<a name="line.239"></a>
<span class="sourceLineNo">240</span>                _comments.add("Error: OrigTime &gt; DestRcvTime");<a name="line.240"></a>
<span class="sourceLineNo">241</span>            }<a name="line.241"></a>
<span class="sourceLineNo">242</span><a name="line.242"></a>
<span class="sourceLineNo">243</span>            _offset = Long.valueOf(((rcvTime - origTime) + (xmitTime - _returnTime)) / 2);<a name="line.243"></a>
<span class="sourceLineNo">244</span>        }<a name="line.244"></a>
<span class="sourceLineNo">245</span>    }<a name="line.245"></a>
<span class="sourceLineNo">246</span><a name="line.246"></a>
<span class="sourceLineNo">247</span>    /**<a name="line.247"></a>
<span class="sourceLineNo">248</span>     * Return list of comments (if any) during processing of NTP packet.<a name="line.248"></a>
<span class="sourceLineNo">249</span>     *<a name="line.249"></a>
<span class="sourceLineNo">250</span>     * @return List or null if not yet computed<a name="line.250"></a>
<span class="sourceLineNo">251</span>     */<a name="line.251"></a>
<span class="sourceLineNo">252</span>    public List&lt;String&gt; getComments()<a name="line.252"></a>
<span class="sourceLineNo">253</span>    {<a name="line.253"></a>
<span class="sourceLineNo">254</span>        return _comments;<a name="line.254"></a>
<span class="sourceLineNo">255</span>    }<a name="line.255"></a>
<span class="sourceLineNo">256</span><a name="line.256"></a>
<span class="sourceLineNo">257</span>    /**<a name="line.257"></a>
<span class="sourceLineNo">258</span>     * Get round-trip network delay. If null then could not compute the delay.<a name="line.258"></a>
<span class="sourceLineNo">259</span>     *<a name="line.259"></a>
<span class="sourceLineNo">260</span>     * @return Long or null if delay not available.<a name="line.260"></a>
<span class="sourceLineNo">261</span>     */<a name="line.261"></a>
<span class="sourceLineNo">262</span>    public Long getDelay()<a name="line.262"></a>
<span class="sourceLineNo">263</span>    {<a name="line.263"></a>
<span class="sourceLineNo">264</span>        return _delay;<a name="line.264"></a>
<span class="sourceLineNo">265</span>    }<a name="line.265"></a>
<span class="sourceLineNo">266</span><a name="line.266"></a>
<span class="sourceLineNo">267</span>    /**<a name="line.267"></a>
<span class="sourceLineNo">268</span>     * Get clock offset needed to adjust local clock to match remote clock. If null then could not<a name="line.268"></a>
<span class="sourceLineNo">269</span>     * compute the offset.<a name="line.269"></a>
<span class="sourceLineNo">270</span>     *<a name="line.270"></a>
<span class="sourceLineNo">271</span>     * @return Long or null if offset not available.<a name="line.271"></a>
<span class="sourceLineNo">272</span>     */<a name="line.272"></a>
<span class="sourceLineNo">273</span>    public Long getOffset()<a name="line.273"></a>
<span class="sourceLineNo">274</span>    {<a name="line.274"></a>
<span class="sourceLineNo">275</span>        return _offset;<a name="line.275"></a>
<span class="sourceLineNo">276</span>    }<a name="line.276"></a>
<span class="sourceLineNo">277</span><a name="line.277"></a>
<span class="sourceLineNo">278</span>    /**<a name="line.278"></a>
<span class="sourceLineNo">279</span>     * Returns NTP message packet.<a name="line.279"></a>
<span class="sourceLineNo">280</span>     *<a name="line.280"></a>
<span class="sourceLineNo">281</span>     * @return NTP message packet.<a name="line.281"></a>
<span class="sourceLineNo">282</span>     */<a name="line.282"></a>
<span class="sourceLineNo">283</span>    public NtpV3Packet getMessage()<a name="line.283"></a>
<span class="sourceLineNo">284</span>    {<a name="line.284"></a>
<span class="sourceLineNo">285</span>        return _message;<a name="line.285"></a>
<span class="sourceLineNo">286</span>    }<a name="line.286"></a>
<span class="sourceLineNo">287</span><a name="line.287"></a>
<span class="sourceLineNo">288</span>    /**<a name="line.288"></a>
<span class="sourceLineNo">289</span>     * Returns time at which time message packet was received by local machine.<a name="line.289"></a>
<span class="sourceLineNo">290</span>     *<a name="line.290"></a>
<span class="sourceLineNo">291</span>     * @return packet return time.<a name="line.291"></a>
<span class="sourceLineNo">292</span>     */<a name="line.292"></a>
<span class="sourceLineNo">293</span>    public long getReturnTime()<a name="line.293"></a>
<span class="sourceLineNo">294</span>    {<a name="line.294"></a>
<span class="sourceLineNo">295</span>        return _returnTime;<a name="line.295"></a>
<span class="sourceLineNo">296</span>    }<a name="line.296"></a>
<span class="sourceLineNo">297</span><a name="line.297"></a>
<span class="sourceLineNo">298</span>}<a name="line.298"></a>




























































</pre>
</div>
</body>
</html>
